This invention relates to a seat back tray table assembly for use on a passenger seat such as used in a passenger aircraft. A conventional tray table is generally mounted to the seat frame of a seat and is movable as desired between a storage position latched against the seat back and a use position where the tray table is lowered to provide a horizontal supporting surface. The tray table is made of lightweight plastic and is subject to ordinary wear and damage from abuse. The aluminum legs of the tray table assembly are also subject to bending due to overloading. Replacement of the tray table conventionally requires substantial time, several tools and the disassembly of several parts. U.S. Pat. No. 4,511,178 discloses two embodiments of a quick release tray table assembly.
In the first embodiment the lower ends of the table legs include a relatively small diameter upper opening joined by a parallel-sided restricted width slot of a smaller dimension to a relatively large diameter lower opening. A pivot stud having a cylindrical outer end portion is fixed against rotation to each frame member. The pivot end portions are interrupted by a pair of opposed parallel flats. The pivot stud can be removed from its normal position within the slot when the seat back is in a break back position. The stud is moved into the lower opening and the legs are then deflected inwardly to remove the stud from the opening.
In the second embodiment a torsion bar is used to lend rigidity to the legs and maintain the legs in a spread position. The tray table can be removed whether or not the seat back is in the break back position. Pivot studs on the seat frame members which support the two table legs are axially aligned with each other and are spaced to fit within axially aligned apertures formed in the two legs of the tray table assembly. Removal is accomplished by deflecting the legs inwardly against the counter thrust of the torsion bar.
Both of these embodiments require inward deflection of the tray table legs. This places strain on the legs and on the mountings of the legs to the tray table. Rough handling during removal of the tray table assembly can damage the mountings thereby making repair and reuse of the components more difficult or impractical.